THE RACE TO UNDERSTAND ANTARCTICA’S MOST TERRIFYING GLACIER

SCIENCE SEASON IN Antarctica begins in November, when noontime temperatures at McMurdo Station climb to a balmy 18 degrees Fahrenheit and the sun hangs in the sky all day and night. For a researcher traveling there from the United States, the route takes time as well as patience. The easiest way is to fly from Los Angeles to Christchurch, New Zealand—a journey of 17 hours, if you’re lucky—and then to McMurdo . . .

Few places in Antarctica are more difficult to reach than Thwaites Glacier, a Florida-sized hunk of frozen water that meets the Amundsen Sea about 800 miles west of McMurdo. Until a decade ago, barely any scientists had ever set foot there, and the glacier’s remoteness, along with its reputation for bad weather, ensured that it remained poorly understood. Yet within the small community of people who study ice for a living, Thwaites has long been the subject of dark speculation. If this mysterious glacier were to “go bad”—glaciologist-­speak for the process by which a glacier breaks down into icebergs and eventually collapses into the ocean—it might be more than a scientific curiosity. Indeed, it might be the kind of event that changes the course of civilization.

In 2014, Eric Rignot, a glaciologist at NASA, concluded that Thwaites was entering a state of “unstoppable” collapse. Even worse, scientists were starting to think that its demise could trigger a larger catastrophe in West Antarctica, the way a rotting support beam might lead to the toppling not only of a wall but of an entire house. Already, Thwaites’ losses were responsible for about 4 percent of global sea-level rise every year.